888/302 rebuild

[jasonnb]

Since I now have my marine 302 apart and have definetly decided on the rebuild, is there anything I should change to make it better/more effecient/ more hp while I'm at it? I don't want to sink tons of extra cash in gust for a couple HP that won't be noticable nayway.

 

[DJ]

Re: 888/302 rebuild

Jaso,<br /><br />You can look at some of the parts from mid eighties OMC 302's. They (OMC) got a few more ponies out of them with different cams, head porting and intake manifolds.

 

[f_inscreenname]

Re: 888/302 rebuild

You can get a master rebuild kit at Northern auto parts (www.northernautoparts.com) for $269.00. Thats cam,lifters,timing sets,pistons,rings,all bearings,oil pump,freeze plugs and all gaskets. You pick any over sized pistons and bearings also you can pick the cam specs. Cheep H.P.--- Try a after market intake (edelbrock) and bump your cam up a little bit. Your motor should be able to handel it after a rebuild. One last tip.Get your motor balanced. It dosent cost that much ($100.00) and will help your motor last alot longer.

 

[jasonnb]

Re: 888/302 rebuild

Thanks for the info. F_inscreenname, I didn't see any marine kits on that site, I'll e-mail them but can you give me more info or a part no? Thanks. Any other info greatly appreciated.

 

[Saperry]

Re: 888/302 rebuild

Northern does not sell marine kits.... Should be the same as an auto kit except freeze plugs and gaskets. The pistons and bearings will work great after you know how much oversize to order, Same with bearings. <br /><br />Again, watch out with your cam spec's. Get somethimg you know will work for marine engines.<br /><br />Best of Luck<br />Sean

 

[jasonnb]

Re: 888/302 rebuild

Ok, let me rehash just to make sure I understand. It's ok to use an auto rebuild kit as long as I use marine gaskets, freeze plugs, and cam?<br /><br />Just want to make sure I understand before I plunk down a pile of cash. Thanks.

 

[Saperry]

Re: 888/302 rebuild

That's about it. The internal pars are the same. How bad off is the motor now that you have it apart. Do re really need to replace pistons? Can you just hone the cyls and rering? Could save a pile of cash..<br /><br />Sean

 

[jasonnb]

Re: 888/302 rebuild

I'm not a mechanic, but the pistons look like toast, but I may show them to the machinist. They may just be corroded. I have a feeling I will end up damaging a couple getting them out since thay are stuck pretty good.<br /><br />The rebuild kit from northern will cost me about $250 + marine gaskets from somewhere else. The big question to me right now is the cam. I'm not sure what the stock cam is in this motor. I have a lobe lift in my Clymer manual, but none of the cam numbers seem to match.

 

[Saperry]

Re: 888/302 rebuild

Take the cam to the machine shop also. Cams can be reground if the lobes are flat. You could also try summit racing they have cams from all the major brands. Find a marine cam that is not too radical. should cost about $100.00 with lifters.<br />Don't forget reeeze plugs....The ones with the Northern kit won't last long they are for cooling system with antifreeze.<br /><br />Also you may check with your machine shop about assembly. Probably not that much and they need to do the machine work. also they assemble engines all day so they know how it's done. Pre lube bearings, Fitting Rings, setting timing...etc<br /><br />Best of Luck<br />Sean

 

[jasonnb]

Re: 888/302 rebuild

Thanks Sean. The cam looks pretty good, no corrosion or gouges at least. I'll definetly ask about re-assembly of the bottem end. I'm just having trouble finding out what the cam should be.

 

[russellackland]

Re: 888/302 rebuild

I rebuilt my 302/888 in 97. Put in a double roller timing chain and heavy duty oil pump. (both upgrades from stock)

 

[f_inscreenname]

Re: 888/302 rebuild

I used the gaskets that came with there rebuild kit. Had the motor in the boat for 4 years befor I got rid of it. No problems. The cam is part of the kit. Why spend another $85.00 on a seperate cam. It is the same thing its just the specs. Look in a Summit book under cams.They always have a guied in every day terms on what you are looking for. Stock specs for a 302/888 combo are lobe lift (intake)0.260/(exhaust)0.273 .Get yourself a "Clymer" Mercruiser shop manual "B740" it has everything on a 888.If you dont do it yourself its always good to know what they are talking about. Brass freez plugs are a must. I think it is a $6.00 upgrade. If you have any questions call them. I have from time to time just doing reserch. There are all quility name brand parts at the cheepest prices I have ever seen. If you are rebuilding a motor that should be a anchor take it to your machine shop to find out it will have to be over sized (cylinders,journals) befor you order your kit it will save you lots of extra time exchanging things.

 

[MGuckin]

Re: 888/302 rebuild

Cam Specs

 

[jasonnb]

Re: 888/302 rebuild

You guys are a wealth of info. <br /><br />I will be dropping everything off at the machine shop tomorrow. <br /><br />The cam that Northern has is rated at 308/312 where the stock is 260/273. That seems like a radical difference.<br /><br />I'll definetly upgrade to double roller and hi cap oil pump. I'll also upgrade to clevite bearings and most likely Molly rings.

 

[Saperry]

Re: 888/302 rebuild

Sounds Like you are on the right track..<br /><br />Maybe I confused you about the gaskets...sorry.<br />The gaskets will work fine, the problem is you will be missing some. The auto application and marine set will likely(I'm really just guessing)<br />be slightly different. You may have to purchase a couple of indvidual gaskets to complete the set.<br />The ones in the auto set that fit will work fine.<br /><br />Hope all goes well<br />Sean

 

[jasonnb]

Re: 888/302 rebuild

Sean, I followed you fairly well. I'm betting I will have to buy Head, waterpumt, ts housing, and manifold gaskets separately. Can you tell me if the cam above is too radical if I go with a new one?

 

[f_inscreenname]

Re: 888/302 rebuild

Stock cams are always real tame and they should be. So motors will last. 260/273 may be a little rough on the idel. It all depends on what you are building. If it were me I would use 10 to 1 flat top pistons with a big cam. But I like speed.

 

[Saperry]

Re: 888/302 rebuild

That is quite a bit of lift. If I were going to put it in a car I would probably use a higer stall speed converter and high rise intake and higer cfm carb.<br /><br />For a boat?<br />What is the rest of the fuel/air delivery sys. <br />What kind of carb, intake, size valves in heads, exh system .. etc do you have. That much lift will likely give a bit of a rough idle. If the stock cam is still in goud shape why change it. Didn't you say the motor was pretty low hrs? Get the kit w/o the new cam if so. <br /><br />To go to a high lift cam and see the full advantage you need to use higher compression pistons, probably more carb, better intake, free flowing exhaust etc. The cam is just one part of the whole system. <br /><br />You could break the bank and have a motor at 375-400hp if you want but if you are boating on a budget(like me) you won't have anything left for gas and trips to the lake. <br /><br />Go back stock and spend your money on something else. That's my opinion...but it depends on how deep your pockets are.<br /><br />Sean

 

[Saperry]

Re: 888/302 rebuild

If you still fell the need to replece the cam I would look for one around 280/290. Stay under 300 and and you should still have a good idle and a smooth running motor.<br /><br />Sean

 

[jasonnb]

Re: 888/302 rebuild

I'll have the stock cam checked. If it is good, I'll re-use it. I'm definetly not versed as to what effect the different cam specs mean, I just want a reliable engine with at least stock power. This engine will be using it's stock 2bbl rochester and stock (new) log manifolds. I thought about upgrading the manifolds, but it is a lot of headache and may not fit properly. The original style will save me some cash since the prev. owner put new risers on last year. I may add a K&N Flame arrestor later.<br /><br />This is a rebuild on a budget (still have some other areas to address like outdrive (wp, gaskets, bearing, alignment) and trailer (bearings, rollers) just to name a few so I don't want to shoot the budget all on the engine.<br /><br />This is definetly a labor of love, yes I could have bought a boat that needed less work/money, but I am fond of this brand and age of boat.